High-Energy Astrophysics with Exoplanet Satellites: AGN, Jets, and Blazars
The new generation of exoplanet-hunting satellites like Kepler and TESS are designed to search for the minute signals of transiting exoplanets around main sequence stars. However, many of their design properties make them ideal instruments for studying time-varying high energy systems, especially accretion disks around supermassive black holes. Such a use requires careful diagnostics and treatment due to dangerous systematics that mimic true variability, but the reward is a rich new parameter space in optical timing. New phenomena discovered include an optical quasi-periodic oscillation, characteristic variability timescales that scale with black hole mass, and a possible supermassive binary self-lensing event. With the much greater sky coverage of TESS and multi-wavelength investigations, the potential exists to search for elusive intermediate-mass black holes that help us understand how billion-solar-mass black holes came to be and to answer fundamental questions about the phenomenology of relativistic jets in radio galaxies and blazars. I will highlight Kepler and K2's discoveries, and describe ongoing efforts to coordinate earthbound and space-based observatories with the monitoring patterns of TESS to exploit this amazing photometer for high energy applications.